A blast in southern Afghanistan which killed 40 people appears to have been a suicide bombing, Afghan officials say.
The explosion ripped through a wedding party in Kandahar province on Wednesday evening, leaving 70 more wounded. Children were among the casualties.
Reports said many of the guests had links to local police or an anti-Taliban militia and that is why they were targeted.
The Taliban, however, have denied any involvement in the attack.
Last week, Afghanistan held a national peace council and endorsed a plan to seek peace with the Taliban. But violence has continued unabated.
On Monday, Nato's International Security Assistance Force (Isaf) lost 10 soldiers on its deadliest day in months.
The explosion ripped through the wedding party at about 2100 local time (1630GMT).
The guests had gathered in Arghandab district just north of the provincial capital of Kandahar, news agency Associated Press quoted Afghan interior ministry spokesman Zemeri Bashary as saying.
Mr Bashary said it was a suicide attack.
"Initial information indicates that a suicide bomber carrying explosives detonated himself among our countrymen at a wedding party in Nagan village in Arghandab district," the interior ministry said.
"Forty of our countrymen, including children, were killed and more than 70 others were injured," it added.
The explosion was reported to have taken place in an area reserved for men.
The groom was one of those wounded in the attack, according to his brother, Mohammad Zanif.
"We don't know what happened. There was an enormous explosion and as a result everyone there was either killed or injured," he told AFP.
Nato forces in Afghanistan blamed the Taliban for the "indiscriminate attack" on the wedding party.
But a Taliban spokesman denied any involvement.
"We condemn such a brutal act," news agency Reuters quoted Qari Yousuf Ahmadi as saying.
Local television appealed to people for blood donations to help those injured.
Outside the hospital mortuary, coffins were spread out on the ground.
In earlier violence on Wednesday, four American Nato soldiers were killed when their helicopter was shot down in neighbouring Helmand province.
The Taliban claimed its fighters had shot down the aircraft with a rocket-propelled grenade in Sangin district.
More than 20 Nato soldiers have died this week.
Last week, Afghan tribal leaders endorsed President Hamid Karzai's plan to seek peace with the Taliban.
The "peace jirga" backed an amnesty and job incentives to induce militants to give up arms.
The Taliban have been waging a battle to overthrow the US-backed government and expel the 130,000 foreign troops there.
Kandahar is set to be the next focus of Nato's military drive against the Taliban.